1. Field of the invention
The present invention relates to a V2X communication device and a transmission power control method thereof. More particularly, the present invention relates to a V2X communication device that controls the increase/decrease of a transmission power such that a proper quantity of data can be transmitted/received according to a radio wave occupancy time or radio wave non-occupancy time when transmitting/receiving data to/from a vehicle so that the collision of data can be minimized. The present invention also relates to a transmission power control method of the V2X communication device.
2. Description of the Prior Art
Recently, V2X (Vehicle to Everything) communication has been developed. The V2X communication includes V2V communication which is vehicle-to-vehicle communication, V2I communication which is vehicle-to-infrastructure communication, and V2N communication which is vehicle-to-nomadic device communication.
The V2X communication forms a network using vehicle-to-vehicle communication, vehicle-to-infrastructure communication, and vehicle-to-nomadic device communication, and transmits/receives various pieces of information through the network so that traffic information, route guidance, various multimedia contents, etc. are shared in order to perform various functions, such as ensuring traffic safety and preventing traffic congestion.
When data is transmitted or received using such V2X communication, an inter-data collision may occur. Currently, in order to prevent the inter-data collision, various collision avoidance logics are applied. Among them, a CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) system causes a transmission side to sense the line status of a reception side, and when a channel is on the inactive status, causes the transmission side to wait for a predetermined time period and then to transmit the data. While the CMSA/CA system is designed to minimize the inter-data collision, the inter-data collision is still unavoidable. Meanwhile, in a case where data is transmitted/received through wireless communication, since different radio wave intensities may be generated depending on communication environments, it is impossible to determine whether there is a data collision using the radio wave intensity while receiving data. Thus, it is necessary to find a method to avoid the data collision as much as possible.